one for upstairs. I recently replaced all the others with new wired versions. I'm not spending $40 at every location for smart units

My thought process is the two z wave ones will notify my phone if we're away.

Also I am hoping Google Home adds the same feature Alexa does which is if it picks up a siren sound it will text you. That feature, if it works, would allow me to not have to update all of the units to be smart.